Engine cases

To see the web we are discussing it is necessary to separate the case halves and photograph the surface that the center gasket goes on. The crank cavity goes all the way to the bottom for the 400, 430, 500 while there is a web as we are calling it that reduces that semi circle by about 3/8 inch for the 240,250,260 or whatever they offered.

see how in upper case half (left case side)
looks like a double wall around crank....that's the "web" used in 240/250 motors

Remove the inner web and just use what melds with the case bottom and you have a 400/430

Too easy

Champion !! many thanks.

like what Justin and I stated on the 1st page.

Problem is information without pictures are harder to understand. This case is stamped as a 250 - 2089 yet didn't have the internal webbing - so not untill Joe posted a pic to describe what he was explaining did it become obivious.

Yep, its already been cut away.

yep cut away. Someone knew you wanted to make a 430! Kharma!

Or the web might have gotten broken from piston skirt breakage so it might have been removed for a more severe case than I corrected a few years ago in one of my 250WR engines

So in order to make my 250 a 430 i need a 430 crank ,rod cylinder piston and top ? Everything else is the same ? /A

different crank, same rod, different cylinder, piston head....all differernt